Shield and tube clamp for subminiature tubes



Dec. 17, 1957 L. A. TWIGG, JR

SHIELD AND TUBE CLAMP FOB SUBHINIATURE TUBES Filed Jan. 14, 1955 FIG. 7.

FIG. 3.

LES TER A. TWIGG, JR.

1 N VEN TOR BY [/ZMkZM ATTORNEYS United States Patent SHIELD AND TUBE CLAMP FOR SUB-MINIATURE TUBES Lester A. Twigg, Jr., Gaithersburg, Md., assignor to the United States of America as represented by the Secretary of the Navy Application January 14, 1955, Serial No. 481,979

2 Claims. (Cl. 174-35) The present invention relates to a shield for miniature tubes and more particularly to a shield adapted to insure electrical connection with electron tubes by its clamping action and to shield said tubes from external electrical disturbances.

Tube shields hitherto available, while relatively succesful in performing their intended function, have nevertheless been so constructed as to require special chassis apertures for their mounting, special tube sockets and so forth. As is frequently the case in experimental work, the necessity of shielding a particular tube is not apparent until the apparatus embodying the tube is placed in operation. Heretofore, in such a case, it was necessary to disassemble the apparatus for the sole purpose of installing a conventional tube shield.

Moreover, from the point of view of the manufacturer of tube shields, prior shields were relatively expensive to produce since the alterations required in the tube socket involved additional handling and machining operations.

Accordin lv, it is an obiect of the present invention to provide a shield for an electron tube which is adapted for installation in existing apparatus without requiring disassembly of said apparatus.

Another object of the present invention resides in the provision of a shield for an electron tube adapted to firmly secure said tube in its socket, thereby minimizing disruption in the operation of said tube due to shock, vibration or like disturbances.

It is a further object of the present invention to provide a shield for electron tubes which is simple in construction and relatively cheap to manufacture.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same be comes better understood by reference to the following detailed description When considered in connection with the accompanying drawings, wherein:

Fig. l is an elevation of the present invention with portions of the shield broken away to reveal an electron tube therein;

Fig. 2 is a plan view of the shield shown in Fig. l; and

Fig. 3 is a bottom view of the shield.

Referring to the drawings, an electron tube 11 of the pin base, miniature type is shown emplaced in a socket 12. The socket 12 may be secured in a suitable aperture in the chassis plate 13 by means of a mounting bracket 14, a machine screw 15 with nut 16, and a bead-headed screw 17 with nut 18.

A cylindrical shield 21 is shown partially enclosing the tube 11. A spiral spring 22 is secured in the upper portion of the shield 21, as by an inwardly directed lip 23, to bear on the upper portion of the tube 11 when the shield 21 is positioned so as to completely enclose said tube.

A tab 24 is formed integrally with the shield 21 and carries at its outer extremity a conventional female snap member 25. As-will be understood, the snap member 25 is arranged to cooperate with the bead-headed screw 17, which functions as a male snap member, to secure firmly the shield 21 to the chassis plate 13. As will be further understood, the screw 17 and snap member 25 establish a low impedance electrical path between the shield 21 and chassis plate 13 thereby effectively shielding the tube 11 from external electrical disturbances.

As best seen in Fig. 3, the female snap member 25 carries the usual U-shaped spring 26, adapted to grip releasably the male snap member. Should it be desired to remove the shield, the snap connection can be released by inserting a screwdriver beneath the female member 25 and gently prying upward.

Since the force required to separate the joined snap members is more than sutficient to overcome the thrust of the spring 22 against the shield 21, the tube 11 is firmly clamped in its socket upon engagement of the male and female snap members.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. A releasable electrical shield assembly, comprising, a conductive shield adapted to enclose the object to be shielded, a conductive base carrying the object to be shielded, a tab projecting from the lower portion of said shield, a female snap member carried by said tab, and a bead-headed screw secured to said base and adapted to cooperate with said female snap member to secure releasably said female snap member and said shield to said base and adapted to establish a conductive electrical path between said shield and said base whereby said shield and said base are maintained at equal electrical potential and the object enclosed by said shield is protected against external electrical disturbances.

2. A releasable assembly for shielding an electron tube and for securing the tube in its socket, comprising, a cylindrical shield adapted to fit over the tube, a spring carried in the upper portion of said shield and adapted to bear on the upper portion of said tube when said shield is fitted thereover, a base including a socket for receiving said tube, a tab projecting from the lower portion of said shield, a female snap member carried by said tab and a male snap member on said base and adapted to cooperate with said female snap member to secured releasably said tab and said shield to said base, whereby said tube is held firmly in place in said socket and is shielded from external electrical disturbances.

References Cited in the file of this patent UNITED STATES PATENTS 2,488,901 Del Camp Nov. 22, 1949 2,531,911 Johnson Nov. 28, 1950 2,533,763 Cacciotti Dec. 12, 1950 FOREIGN PATENTS 622,075 Great Britain Apr. 26, 1949 

